That seems obviously unwise and reasonable for the compiler to complain. Or: void demo(int i) { int a[10]; for( int j = 0; j < 10000; j++ ) { a[13 * i % 7 + 3] += j; stuffit(i); } } With And a 'class' is not a temporary, the reference to it is. But how to implement this in a practical way is the question. have a peek at these guys

But do you have a cool idea to update just one property like X? –nawfal Apr 25 '13 at 16:57 For structs which encapsualate a collection of independent but See Also System.Collections.Generic.Dictionary Class, System.Collections.Generic Namespace Dictionary.GetEnumerator Method public Dictionary.Enumerator GetEnumerator() Summary Returns an enumerator that can be used to iterate over the dictionary. P: n/a Zytan This returns the following error: "Cannot modify the return value of 'System.Collections.Generic.List.this[int]' because it is not a variable" and I have no idea why! Can Egyptian citizen visit Armenia on valid USA visa?

C# Dictionary Struct Key

If you want to change just the X value, you need to do something like this: Origin = new Point(10, Origin.Y); share|improve this answer answered Nov 17 '09 at 9:49 Greg The inconsistent behaviour of structs and classes is confusing. –nawfal Apr 25 '13 at 18:37 | show 3 more comments up vote 0 down vote The problem is that you point See Also System.Collections.Generic.Dictionary Class, System.Collections.Generic Namespace Dictionary.Item Property public TValue this[TKey key] { get; set; } Summary Gets or sets the value associated with the specified key. Yes, it could.

Of course, C++ does it's fair share of hiding things, too, so an identical argument could be made on C++ vs assembly. As far as I can recall, C++ does not use the "const" information in the way that Zytan is asking for C# to. The code above won't work even if you manage to compile it.Why don't you make InventoryRecord a class? I guess there's good and bad that comes with that.

What if the implementation changes? Dictionary C# Not the answer you're looking for? To some degree, a good program / programmer needs both. I will edit it –nawfal Apr 25 '13 at 16:41 @supercat this is the first time I'm thinking of your point, makes a lot of sense!

C# Dictionary Struct Value

Of course, you might want to have mutable fields for caching purposes (e.g. This method also returns false if key was not found in the dictionary. C# Dictionary Struct Key Just say no to mutable structs, basically :) Yup! :) But, it just doesn't seem fair, since the language isn't quite 'complete', yet. Mutable Struct A key cannot be null, but a value can be, if the value type TValue is a reference type.

Zytan May 14 '07 #5 P: n/a Peter Duniho On Mon, 14 May 2007 11:38:10 -0700, Zytan http://humerussoftware.com/cannot-modify/cannot-modify.php Parameters key The key of the element to locate in the dictionary. more stack exchange communities company blog Stack Exchange Inbox Reputation and Badges sign up log in tour help Tour Start here for a quick overview of the site Help Center Detailed Things like overloading hiding certain type conversions, for example. C# Cannot Modify The Return Value Of Because It Is Not A Variable

You should only call const-methods on temporaries!" Zytan May 15 '07 #26 P: n/a Zytan Well, note that C++ implements it by including the "const" right in the function name. Why did the best potions master have greasy hair? But, perhaps his situations wouldn't have happened had "const" been used from the get-go, though. check my blog If you get a reference from a List<>, then yes you get a copy of the reference, just like you get a copy of a value type.

There's a time and place for a value type, and in fact they even have their place in lists. C# Struct Vs Class Perhaps an architectural redesign wasn't worth having "const" in there, so they cast it away, thinking "const is useless, you have to cast it away to work", and that's the most Usually you don't even want to be calling a method AT ALL on one, so I don't think the warning would happen too often when it shouldn't (but that's based on

Why did the best potions master have greasy hair? I guess there's good and bad that comes with that. Secondly, the reason taking "const" out prevents it from compiling is that you can't initialize an array with a size that isn't known at compile time. Without "const", aliasing analysis reveals that i can change, therefore the computation must be executed inside the loop, with little opportunity for optimization.

Too much professionally-written C++ code (including some of my own) simply does not use "const" for you to make that claim. If one supplier has delayed your project schedule should the other suppliers on the project be alerted to the new timeline? You're going to have to be far more specific -- there are a lot of different libraries grouped under the heading of "the Windows API" and all the core ones are http://humerussoftware.com/cannot-modify/cannot-modify-the-return-value.php Did a thief think he could conceal his identity from security cameras by putting lemon juice on his face?

Jessespike · Sep 17, 2012 at 03:08 PM 0 Share Is there a reason why you cannot store the value a temp variable like the error suggests? If System.Collections.Generic.Dictionary.Count already equals the capacity, the capacity of the dictionary is increased. more stack exchange communities company blog Stack Exchange Inbox Reputation and Badges sign up log in tour help Tour Start here for a quick overview of the site Help Center Detailed